drm/radeon: do a posting read in r100_set_irq
To make sure the writes go through the pci bridge.
bug:
https://bugzilla.kernel.org/show_bug.cgi?id=90741
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 279801c..04f2514 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -728,6 +728,10 @@
tmp |= RADEON_FP2_DETECT_MASK;
}
WREG32(RADEON_GEN_INT_CNTL, tmp);
+
+ /* read back to post the write */
+ RREG32(RADEON_GEN_INT_CNTL);
+
return 0;
}